micropython/extmod/modssl_axtls.c
Damien George e8a4c1dd53 extmod/modssl: Add SSLContext class.
This commit adds the SSLContext class to the ssl module, and retains the
existing ssl.wrap_socket() function to maintain backwards compatibility.

CPython deprecated the ssl.wrap_socket() function since CPython 3.7 and
instead one should use ssl.SSLContext().wrap_socket().  This commit makes
that possible.

For the axtls implementation:
- ssl.SSLContext is added, although it doesn't hold much state because
  axtls requires calling ssl_ctx_new() for each new socket
- ssl.SSLContext.wrap_socket() is added
- ssl.PROTOCOL_TLS_CLIENT and ssl.PROTOCOL_TLS_SERVER are added

For the mbedtls implementation:
- ssl.SSLContext is added, and holds most of the mbedtls state
- ssl.verify_mode is added (getter and setter)
- ssl.SSLContext.wrap_socket() is added
- ssl.PROTOCOL_TLS_CLIENT and ssl.PROTOCOL_TLS_SERVER are added

The signatures match CPython:
- SSLContext(protocol)
- SSLContext.wrap_socket(sock, *, server_side=False,
    do_handshake_on_connect=True, server_hostname=None)

The existing ssl.wrap_socket() functions retain their existing signature.

Signed-off-by: Damien George <damien@micropython.org>
2023-06-26 16:34:41 +10:00

462 lines
16 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2015-2019 Paul Sokolovsky
* Copyright (c) 2023 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdio.h>
#include <string.h>
#include "py/runtime.h"
#include "py/stream.h"
#include "py/objstr.h"
#if MICROPY_PY_SSL && MICROPY_SSL_AXTLS
#include "ssl.h"
#define PROTOCOL_TLS_CLIENT (0)
#define PROTOCOL_TLS_SERVER (1)
// This corresponds to an SSLContext object.
typedef struct _mp_obj_ssl_context_t {
mp_obj_base_t base;
mp_obj_t key;
mp_obj_t cert;
} mp_obj_ssl_context_t;
// This corresponds to an SSLSocket object.
typedef struct _mp_obj_ssl_socket_t {
mp_obj_base_t base;
mp_obj_t sock;
SSL_CTX *ssl_ctx;
SSL *ssl_sock;
byte *buf;
uint32_t bytes_left;
bool blocking;
} mp_obj_ssl_socket_t;
struct ssl_args {
mp_arg_val_t key;
mp_arg_val_t cert;
mp_arg_val_t server_side;
mp_arg_val_t server_hostname;
mp_arg_val_t do_handshake;
};
STATIC const mp_obj_type_t ssl_context_type;
STATIC const mp_obj_type_t ssl_socket_type;
STATIC mp_obj_t ssl_socket_make_new(mp_obj_ssl_context_t *ssl_context, mp_obj_t sock,
bool server_side, bool do_handshake_on_connect, mp_obj_t server_hostname);
/******************************************************************************/
// Helper functions.
// Table of error strings corresponding to SSL_xxx error codes.
STATIC const char *const ssl_error_tab1[] = {
"NOT_OK",
"DEAD",
"CLOSE_NOTIFY",
"EAGAIN",
};
STATIC const char *const ssl_error_tab2[] = {
"CONN_LOST",
"RECORD_OVERFLOW",
"SOCK_SETUP_FAILURE",
NULL,
"INVALID_HANDSHAKE",
"INVALID_PROT_MSG",
"INVALID_HMAC",
"INVALID_VERSION",
"UNSUPPORTED_EXTENSION",
"INVALID_SESSION",
"NO_CIPHER",
"INVALID_CERT_HASH_ALG",
"BAD_CERTIFICATE",
"INVALID_KEY",
NULL,
"FINISHED_INVALID",
"NO_CERT_DEFINED",
"NO_CLIENT_RENOG",
"NOT_SUPPORTED",
};
STATIC NORETURN void ssl_raise_error(int err) {
MP_STATIC_ASSERT(SSL_NOT_OK - 3 == SSL_EAGAIN);
MP_STATIC_ASSERT(SSL_ERROR_CONN_LOST - 18 == SSL_ERROR_NOT_SUPPORTED);
// Check if err corresponds to something in one of the error string tables.
const char *errstr = NULL;
if (SSL_NOT_OK >= err && err >= SSL_EAGAIN) {
errstr = ssl_error_tab1[SSL_NOT_OK - err];
} else if (SSL_ERROR_CONN_LOST >= err && err >= SSL_ERROR_NOT_SUPPORTED) {
errstr = ssl_error_tab2[SSL_ERROR_CONN_LOST - err];
}
// Unknown error, just raise the error code.
if (errstr == NULL) {
mp_raise_OSError(err);
}
// Construct string object.
mp_obj_str_t *o_str = m_new_obj_maybe(mp_obj_str_t);
if (o_str == NULL) {
mp_raise_OSError(err);
}
o_str->base.type = &mp_type_str;
o_str->data = (const byte *)errstr;
o_str->len = strlen((char *)o_str->data);
o_str->hash = qstr_compute_hash(o_str->data, o_str->len);
// Raise OSError(err, str).
mp_obj_t args[2] = { MP_OBJ_NEW_SMALL_INT(err), MP_OBJ_FROM_PTR(o_str)};
nlr_raise(mp_obj_exception_make_new(&mp_type_OSError, 2, 0, args));
}
/******************************************************************************/
// SSLContext type.
STATIC mp_obj_t ssl_context_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 1, 1, false);
// The "protocol" argument is ignored in this implementation.
// Create SSLContext object.
#if MICROPY_PY_SSL_FINALISER
mp_obj_ssl_context_t *self = m_new_obj_with_finaliser(mp_obj_ssl_context_t);
#else
mp_obj_ssl_context_t *self = m_new_obj(mp_obj_ssl_context_t);
#endif
self->base.type = type_in;
self->key = mp_const_none;
self->cert = mp_const_none;
return MP_OBJ_FROM_PTR(self);
}
STATIC void ssl_context_load_key(mp_obj_ssl_context_t *self, mp_obj_t key_obj, mp_obj_t cert_obj) {
self->key = key_obj;
self->cert = cert_obj;
}
STATIC mp_obj_t ssl_context_wrap_socket(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_server_side, ARG_do_handshake_on_connect, ARG_server_hostname };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_server_side, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
{ MP_QSTR_do_handshake_on_connect, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
{ MP_QSTR_server_hostname, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
};
// Parse arguments.
mp_obj_ssl_context_t *self = MP_OBJ_TO_PTR(pos_args[0]);
mp_obj_t sock = pos_args[1];
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 2, pos_args + 2, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// Create and return the new SSLSocket object.
return ssl_socket_make_new(self, sock, args[ARG_server_side].u_bool,
args[ARG_do_handshake_on_connect].u_bool, args[ARG_server_hostname].u_obj);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(ssl_context_wrap_socket_obj, 2, ssl_context_wrap_socket);
STATIC const mp_rom_map_elem_t ssl_context_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_wrap_socket), MP_ROM_PTR(&ssl_context_wrap_socket_obj) },
};
STATIC MP_DEFINE_CONST_DICT(ssl_context_locals_dict, ssl_context_locals_dict_table);
STATIC MP_DEFINE_CONST_OBJ_TYPE(
ssl_context_type,
MP_QSTR_SSLContext,
MP_TYPE_FLAG_NONE,
make_new, ssl_context_make_new,
locals_dict, &ssl_context_locals_dict
);
/******************************************************************************/
// SSLSocket type.
STATIC mp_obj_t ssl_socket_make_new(mp_obj_ssl_context_t *ssl_context, mp_obj_t sock,
bool server_side, bool do_handshake_on_connect, mp_obj_t server_hostname) {
#if MICROPY_PY_SSL_FINALISER
mp_obj_ssl_socket_t *o = m_new_obj_with_finaliser(mp_obj_ssl_socket_t);
#else
mp_obj_ssl_socket_t *o = m_new_obj(mp_obj_ssl_socket_t);
#endif
o->base.type = &ssl_socket_type;
o->buf = NULL;
o->bytes_left = 0;
o->sock = sock;
o->blocking = true;
uint32_t options = SSL_SERVER_VERIFY_LATER;
if (!do_handshake_on_connect) {
options |= SSL_CONNECT_IN_PARTS;
}
if (ssl_context->key != mp_const_none) {
options |= SSL_NO_DEFAULT_KEY;
}
if ((o->ssl_ctx = ssl_ctx_new(options, SSL_DEFAULT_CLNT_SESS)) == NULL) {
mp_raise_OSError(MP_EINVAL);
}
if (ssl_context->key != mp_const_none) {
size_t len;
const byte *data = (const byte *)mp_obj_str_get_data(ssl_context->key, &len);
int res = ssl_obj_memory_load(o->ssl_ctx, SSL_OBJ_RSA_KEY, data, len, NULL);
if (res != SSL_OK) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid key"));
}
data = (const byte *)mp_obj_str_get_data(ssl_context->cert, &len);
res = ssl_obj_memory_load(o->ssl_ctx, SSL_OBJ_X509_CERT, data, len, NULL);
if (res != SSL_OK) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid cert"));
}
}
if (server_side) {
o->ssl_sock = ssl_server_new(o->ssl_ctx, (long)sock);
} else {
SSL_EXTENSIONS *ext = ssl_ext_new();
if (server_hostname != mp_const_none) {
ext->host_name = (char *)mp_obj_str_get_str(server_hostname);
}
o->ssl_sock = ssl_client_new(o->ssl_ctx, (long)sock, NULL, 0, ext);
if (do_handshake_on_connect) {
int r = ssl_handshake_status(o->ssl_sock);
if (r != SSL_OK) {
if (r == SSL_CLOSE_NOTIFY) { // EOF
r = MP_ENOTCONN;
} else if (r == SSL_EAGAIN) {
r = MP_EAGAIN;
}
ssl_raise_error(r);
}
}
}
return o;
}
STATIC mp_uint_t ssl_socket_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errcode) {
mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
if (o->ssl_sock == NULL) {
*errcode = EBADF;
return MP_STREAM_ERROR;
}
while (o->bytes_left == 0) {
mp_int_t r = ssl_read(o->ssl_sock, &o->buf);
if (r == SSL_OK) {
// SSL_OK from ssl_read() means "everything is ok, but there's
// no user data yet". It may happen e.g. if handshake is not
// finished yet. The best way we can treat it is by returning
// EAGAIN. This may be a bit unexpected in blocking mode, but
// default is to perform complete handshake in constructor, so
// this should not happen in blocking mode. On the other hand,
// in nonblocking mode EAGAIN (comparing to the alternative of
// looping) is really preferable.
if (o->blocking) {
continue;
} else {
goto eagain;
}
}
if (r < 0) {
if (r == SSL_CLOSE_NOTIFY || r == SSL_ERROR_CONN_LOST) {
// EOF
return 0;
}
if (r == SSL_EAGAIN) {
eagain:
r = MP_EAGAIN;
}
*errcode = r;
return MP_STREAM_ERROR;
}
o->bytes_left = r;
}
if (size > o->bytes_left) {
size = o->bytes_left;
}
memcpy(buf, o->buf, size);
o->buf += size;
o->bytes_left -= size;
return size;
}
STATIC mp_uint_t ssl_socket_write(mp_obj_t o_in, const void *buf, mp_uint_t size, int *errcode) {
mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(o_in);
if (o->ssl_sock == NULL) {
*errcode = EBADF;
return MP_STREAM_ERROR;
}
mp_int_t r;
eagain:
r = ssl_write(o->ssl_sock, buf, size);
if (r == 0) {
// see comment in ssl_socket_read above
if (o->blocking) {
goto eagain;
} else {
r = SSL_EAGAIN;
}
}
if (r < 0) {
if (r == SSL_CLOSE_NOTIFY || r == SSL_ERROR_CONN_LOST) {
return 0; // EOF
}
if (r == SSL_EAGAIN) {
r = MP_EAGAIN;
}
*errcode = r;
return MP_STREAM_ERROR;
}
return r;
}
STATIC mp_uint_t ssl_socket_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg, int *errcode) {
mp_obj_ssl_socket_t *self = MP_OBJ_TO_PTR(o_in);
if (request == MP_STREAM_CLOSE && self->ssl_sock != NULL) {
ssl_free(self->ssl_sock);
ssl_ctx_free(self->ssl_ctx);
self->ssl_sock = NULL;
}
// Pass all requests down to the underlying socket
return mp_get_stream(self->sock)->ioctl(self->sock, request, arg, errcode);
}
STATIC mp_obj_t ssl_socket_setblocking(mp_obj_t self_in, mp_obj_t flag_in) {
mp_obj_ssl_socket_t *o = MP_OBJ_TO_PTR(self_in);
mp_obj_t sock = o->sock;
mp_obj_t dest[3];
mp_load_method(sock, MP_QSTR_setblocking, dest);
dest[2] = flag_in;
mp_obj_t res = mp_call_method_n_kw(1, 0, dest);
o->blocking = mp_obj_is_true(flag_in);
return res;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(ssl_socket_setblocking_obj, ssl_socket_setblocking);
STATIC const mp_rom_map_elem_t ssl_socket_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
{ MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
{ MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
{ MP_ROM_QSTR(MP_QSTR_setblocking), MP_ROM_PTR(&ssl_socket_setblocking_obj) },
{ MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&mp_stream_close_obj) },
#if MICROPY_PY_SSL_FINALISER
{ MP_ROM_QSTR(MP_QSTR___del__), MP_ROM_PTR(&mp_stream_close_obj) },
#endif
};
STATIC MP_DEFINE_CONST_DICT(ssl_socket_locals_dict, ssl_socket_locals_dict_table);
STATIC const mp_stream_p_t ssl_socket_stream_p = {
.read = ssl_socket_read,
.write = ssl_socket_write,
.ioctl = ssl_socket_ioctl,
};
STATIC MP_DEFINE_CONST_OBJ_TYPE(
ssl_socket_type,
MP_QSTR_SSLSocket,
MP_TYPE_FLAG_NONE,
protocol, &ssl_socket_stream_p,
locals_dict, &ssl_socket_locals_dict
);
/******************************************************************************/
// ssl module.
STATIC mp_obj_t mod_ssl_wrap_socket(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum {
ARG_key,
ARG_cert,
ARG_server_side,
ARG_server_hostname,
ARG_do_handshake,
};
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_key, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
{ MP_QSTR_cert, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
{ MP_QSTR_server_side, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
{ MP_QSTR_server_hostname, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
{ MP_QSTR_do_handshake, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} },
};
// Parse arguments.
mp_obj_t sock = pos_args[0];
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// Create SSLContext.
mp_int_t protocol = args[ARG_server_side].u_bool ? PROTOCOL_TLS_SERVER : PROTOCOL_TLS_CLIENT;
mp_obj_t ssl_context_args[1] = { MP_OBJ_NEW_SMALL_INT(protocol) };
mp_obj_ssl_context_t *ssl_context = MP_OBJ_TO_PTR(ssl_context_make_new(&ssl_context_type, 1, 0, ssl_context_args));
// Load key and cert if given.
if (args[ARG_key].u_obj != mp_const_none) {
ssl_context_load_key(ssl_context, args[ARG_key].u_obj, args[ARG_cert].u_obj);
}
// Create and return the new SSLSocket object.
return ssl_socket_make_new(ssl_context, sock, args[ARG_server_side].u_bool,
args[ARG_do_handshake].u_bool, args[ARG_server_hostname].u_obj);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(mod_ssl_wrap_socket_obj, 1, mod_ssl_wrap_socket);
STATIC const mp_rom_map_elem_t mp_module_ssl_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_ssl) },
// Functions.
{ MP_ROM_QSTR(MP_QSTR_wrap_socket), MP_ROM_PTR(&mod_ssl_wrap_socket_obj) },
// Classes.
{ MP_ROM_QSTR(MP_QSTR_SSLContext), MP_ROM_PTR(&ssl_context_type) },
// Constants.
{ MP_ROM_QSTR(MP_QSTR_PROTOCOL_TLS_CLIENT), MP_ROM_INT(PROTOCOL_TLS_CLIENT) },
{ MP_ROM_QSTR(MP_QSTR_PROTOCOL_TLS_SERVER), MP_ROM_INT(PROTOCOL_TLS_SERVER) },
};
STATIC MP_DEFINE_CONST_DICT(mp_module_ssl_globals, mp_module_ssl_globals_table);
const mp_obj_module_t mp_module_ssl = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t *)&mp_module_ssl_globals,
};
MP_REGISTER_EXTENSIBLE_MODULE(MP_QSTR_ssl, mp_module_ssl);
#endif // MICROPY_PY_SSL && MICROPY_SSL_AXTLS